Axum

Axum, also called Aksum, was an Ethiopian kingdom on the Horn of Africa. From 400 BC to 940 AD, the Kingdom of Axum reigned over Ethiopia, Somalia, and Eritrea, and co-existed with larger kingdoms such as the Ptolemaic Empire, Meroe, Blemmyes, and the Kushites. The Kingdom of Axum is credited with the first toll-booths, collecting taxes from merchants and travelers. They fought Meroe constantly, but maintained their independence until they were conquered by Gudit of Damot in 940 AD.

History
Axum was an ivory trading nation first mentioned by the " Periplus of the Erythraean Sea" in the 1st century AD. It was founded by Sabaeans from Yemen, and controlled Eritrea, Ethiopia, and the Sudan. The kingdom flourished through collecting taxes in the world's first tollbooths, and also traded African goods such as ivory from elephants. Their capital was at the eponymous city of Aksum, and they extended their empire through campaigns against neighboring hunter-gatherer tribes.

In the 3rd century BC they fought wars against the Meroe kingdom to the north, and maintained a peaceful coexistence with the Kingdom of the Ptolemies and the Blemmyes faction for decades.

In the 200s AD, it was named one of the world's greatest powers along with the Sassanid Empire, Roman Empire, and the Eastern Han. In 328, they converted to Christianity and they conquered the Kushites in 350 AD. In 525 AD their king Caleb of Axum conquered the Yemen from the Himyarite Empire, a Yemenite Jewish kingdom, but by the later 6th and 7th centuries, their lands in Asia were conquered by the Islamic Caliphate. In 960, Queen Judith of Damot, a Beta Jewish (Ethiopian Jew) queen, destroyed Axum and conquered it, but her kingdom would be taken over by Alodia and Makuria soon after.